ae_epoll.c

   1 /* Linux epoll(2) based ae.c module
   2  * Copyright (C) 2009 Salvatore Sanfilippo - antirez@gmail.com
   3  * Released under the BSD license. See the COPYING file for more info. */
   4
   5 #include <sys/epoll.h>
   6
   7 typedef struct aeApiState {
   8     int epfd;
   9     struct epoll_event events[AE_SETSIZE];
  10 } aeApiState;
  11
  12 static int aeApiCreate(aeEventLoop *eventLoop) {
  13     aeApiState *state = zmalloc(sizeof(aeApiState));
  14
  15     if (!state) return -1;
  16     state->epfd = epoll_create(1024); /* 1024 is just an hint for the kernel */
  17     if (state->epfd == -1) return -1;
  18     eventLoop->apidata = state;
  19     return 0;
  20 }
  21
  22 static void aeApiFree(aeEventLoop *eventLoop) {
  23     aeApiState *state = eventLoop->apidata;
  24
  25     close(state->epfd);
  26     zfree(state);
  27 }
  28
  29 static int aeApiAddEvent(aeEventLoop *eventLoop, int fd, int mask) {
  30     aeApiState *state = eventLoop->apidata;
  31     struct epoll_event ee;
  32     /* If the fd was already monitored for some event, we need a MOD
  33      * operation. Otherwise we need an ADD operation. */
  34     int op = eventLoop->events[fd].mask == AE_NONE ?
  35             EPOLL_CTL_ADD : EPOLL_CTL_MOD;
  36
  37     ee.events = 0;
  38     mask |= eventLoop->events[fd].mask; /* Merge old events */
  39     if (mask & AE_READABLE) ee.events |= EPOLLIN;
  40     if (mask & AE_WRITABLE) ee.events |= EPOLLOUT;
  41     if (mask & AE_EXCEPTION) ee.events |= EPOLLPRI;
  42     ee.data.u64 = 0; /* avoid valgrind warning */
  43     ee.data.fd = fd;
  44     if (epoll_ctl(state->epfd,op,fd,&ee) == -1) return -1;
  45     return 0;
  46 }
  47
  48 static void aeApiDelEvent(aeEventLoop *eventLoop, int fd, int delmask) {
  49     aeApiState *state = eventLoop->apidata;
  50     struct epoll_event ee;
  51     int mask = eventLoop->events[fd].mask & (~delmask);
  52
  53     ee.events = 0;
  54     if (mask & AE_READABLE) ee.events |= EPOLLIN;
  55     if (mask & AE_WRITABLE) ee.events |= EPOLLOUT;
  56     if (mask & AE_EXCEPTION) ee.events |= EPOLLPRI;
  57     ee.data.u64 = 0; /* avoid valgrind warning */
  58     ee.data.fd = fd;
  59     if (mask != AE_NONE) {
  60         epoll_ctl(state->epfd,EPOLL_CTL_MOD,fd,&ee);
  61     } else {
  62         /* Note, Kernel < 2.6.9 requires a non null event pointer even for
  63          * EPOLL_CTL_DEL. */
  64         epoll_ctl(state->epfd,EPOLL_CTL_DEL,fd,&ee);
  65     }
  66 }
  67
  68 static int aeApiPoll(aeEventLoop *eventLoop, struct timeval *tvp) {
  69     aeApiState *state = eventLoop->apidata;
  70     int retval, numevents = 0;
  71
  72     retval = epoll_wait(state->epfd,state->events,AE_SETSIZE,
  73             tvp ? (tvp->tv_sec*1000 + tvp->tv_usec/1000) : -1);
  74     if (retval > 0) {
  75         int j;
  76
  77         numevents = retval;
  78         for (j = 0; j < numevents; j++) {
  79             int mask = 0;
  80             struct epoll_event *e = state->events+j;
  81
  82             if (e->events & EPOLLIN) mask |= AE_READABLE;
  83             if (e->events & EPOLLOUT) mask |= AE_WRITABLE;
  84             if (e->events & EPOLLPRI) mask |= AE_EXCEPTION;
  85             eventLoop->fired[j].fd = e->data.fd;
  86             eventLoop->fired[j].mask = mask;
  87         }
  88     }
  89     return numevents;
  90 }
  91
  92 static char *aeApiName(void) {
  93     return "epoll";
  94 }